Mapping Question

I am working with a Covast ASC_X12_811_004_010_DEFAULT_X schema and have a question on mapping child records of the HL Hierarchical Level.

The HL Hierarchical Level has these elements:
Hierarchical ID Number
Hierarchical Parent ID Number
Hierarchical Level Code
Hierarchical Child Code

My destination schema has multiple records to map to:
-Level- -Hierarchical Level Code-
BillDetailLevel1 1
BillDetailLevel2 4
BillDetailLevel3 5,6, NOT 8
BillDetailLevel3Leaf 8
BillDetailLevel4 6,7, NOT 8
BillDetailLevel4Leaf 8
BillDetailLevel5 7
BillDetailLevel5Leaf 8
BillDetailLevel6Leaf 8

As you can see BillDetailLevel3Leaf has the same level code as BillDetailLevel4Leaf. When mapping I can get the Parent ID Number but I really need the Parent Level Code. How would I determine the parent level in order to map to a particular destination record?